We’ve already covered why studying with official practice questions is the best way to prepare for the GMAT. But even if you come up with the correct answer to an official problem, you still might not understand the underlying principles used to create that particular question, leaving yourself open to traps and pitfalls set by the test writers. In the explanations below, I will use some of the core tenets of the Menlo Coaching GMAT curriculum to breakdown two official GMAT critical reasoning practice questions and provide important principles for correctly attacking this question type in the future.
For most students, critical reasoning is a completely new exercise—a question type never before seen or practiced. The instructions in the GMAT Official Guide state: “Answering Critical Reasoning questions requires no specialized knowledge. You don’t need to know the terminology or conventions of formal logic.” While technically this may be true, it certainly doesn’t hurt to have a formal understanding of common logical fallacies and to be comfortable with terminology!
Which of the following most logically completes the argument?
A new machine for harvesting corn will allow rows to be planted only fifteen inches apart, instead of the usual thirty inches. Corn planted this closely will produce lower yields per plant. Nevertheless, the new machine will allow corn growers to double their profits per acre because ________.
Correct answer is (A).
When creating GMAT critical reasoning questions, test writers know exactly what you will be thinking about when certain scenarios are developed, and they deviously use your own mind against you. You must learn to fight this natural instinct: always question the first thing you think about in a critical reasoning question…it is usually a trap! Just as the positive/negative number properties were used to distract you in the DS sample question covered here, so the “obvious” answer plays the same role here.
Most people immediately gravitate to (D) in this question (you are looking for a premise that improves the quality of the conclusion): if farmers are able to plant twice as much corn because they have reduced the width between rows, then that would explain how they can make a lot more profit. Answer choice (D) seems perfect and most people pick it: “with the spacing between rows cut by half, the number of plants grown per acre will almost double.”
However, in critical reasoning you must learn to be extremely particular with the given conclusion. The conclusion in this stimulus is the following: “the new machine will allow corn growers to double their profits per acre.” Yet, you are also given an important fact in the argument that will qualify the statement in (D): “Corn planted this closely will produce lower yields per plant.” If you plant twice as much corn but you know for a fact that the closer rows will mean a lower yield per plant, then it is impossible to double profits from twice as many plants in closer rows. Additionally, the answer in (D) states “almost double,” which makes it even weaker. You want the answer to be (D) because that is what your mind anticipates, but numerous elements make it conclusively incorrect. It is really not telling you anything new and it does not at all explain how the farmers can still double profits even if yields are lower per plant.
The correct answer (A) is not expected nor particularly satisfying, but it is the only one that works. If the need for costly weed control is lessened by the narrow rows, then the combination of more corn and lower expenses can explain how profits would be doubled by farmers even with lower yields per plant. Remember that profits involve two components: revenue, which in this argument cannot explain the doubling of profits by itself, and costs, which if reduced along with increased revenue from more corn can explain a doubling of profit even with reduced yields. With practice, you will learn to be very suspicious about your first reaction when reading GMAT critical reasoning questions.
Editorial in Krenlandian Newspaper:
Krenland’s steelmakers are losing domestic sales because of lower-priced imports, in many cases because foreign governments subsidize their steel industries in ways that are banned by international treaties. But whatever the cause, the cost is ultimately going to be jobs in Krenland’s steel industry. Therefore, it would protect not only steel companies but also industrial employment in Krenland if our government took measures to reduce cheap steel imports.
Which of the following, if true, most seriously weakens the editorial’s argument?
Correct answer is (C).
This moderately difficult CR question presents a great example of one of the oldest tricks in the CR playbook: the “word shift” con. It is extremely common for test writers to develop a detailed and elaborate argument that then involves a subtle shift in wording or scope when moving from the premises to the conclusion.
When attacking a “weaken” question like this, you should always start by deconstructing the argument and understanding exactly the line of reasoning. To summarize this argument:
Premise One: Krenland’s steelmakers are losing domestic sales because of lower priced imports that often result from unfair practices banned by international treaties.
Premise Two: These imports are going to result in job losses in Krenland’s steel industry
Conclusion: The government should reduce cheap steel imports in order to protect not only the steel industry but also industrial employment in Krenland.
Did you notice that shift in wording and scope in bold? If you do, this problem is relatively easy; if you don’t, you will waste a lot of time and probably get it wrong. Because the whole argument is about the steel industry, many people overlook the change in shift and wording from “employment in the steel industry” to “industrial employment.” They are not the same thing! If you see this shift, then you will recognize that the conclusion has a serious flaw: how do we know that stopping cheap steel imports is good for other industrial companies in Krenland and thus industrial employment in general?
The goal of this question (which you should be crystal clear on before moving to answer choices) is to attack the line of reasoning and expose a flaw in the argument. If you notice the shift in scope, then you can anticipate the answer: what if most industries in Krenland greatly benefit from the cheap steel because their products become more competitive domestically and internationally? In other words, it is entirely possible that stopping cheap steel imports will HURT industrial employment, which the conclusion suggests this action will protect.
Answer choice (C) perfectly exposes this potential scenario and is thus correct.
When analyzed carefully, you see that none of the other answers do anything to show why stopping cheap imports will NOT protect steelmakers or industrial employment. Most of these incorrect answers seek to explain why the imports are cheap, which is not important but is satisfying for many test-takers who don’t notice the word shift:
(A) does nothing to weaken the argument because the issue at play for steel makers is their domestic sales, not their exports.
(B) the international treaties are not relevant to the conclusion – why the imports are cheap does not matter.
(A) again, it is not important to know how or why the imports are cheap – the conclusion is just to stop them
(B) this can again explain the difference in prices for steel, but does not address the conclusion.
To succeed in critical reasoning, you must be able to recognize logical flaws and “tricks” quickly. This type of word shift is extremely common and becomes easy to notice when you are trained to look for it. As I joke with students: “there is no such thing as a synonym in GMAT critical reasoning!” If there is a slight change in wording or scope, it almost surely matters for recognizing a flaw in the given argument.
To succeed on GMAT critical reasoning questions, it is essential that you learn defined strategies and best practices, yet most people who study on their own do not do that. They simply use their smarts and logic to answer these questions, an approach that breaks down on harder examples in the time-pressured exam environment. As you can see with the other sample questions, you must learn how GMAT critical reasoning questions are made difficult and what mindsets and strategies allow you to overcome this difficulty. If you look carefully at this well-crafted question below from the official practice tests, you should see a very similar scenario to the “shiny penny” con as described in our GMAT data sufficiency sample questions and explanations. The same mindset and thought process is tested over and over in this exam through all the different question types! Keep this in mind as you pursue your GMAT prep, no matter what form that prep takes.
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